Shutting down Windows 7 automatically 10 minutes from now

The shutdown command line command is what you're after, with /t 600 you'll get a 600 second (10 minute) delay other options define the shutdown process. In your case I suspect you'll want shutdown /t 600 /s.

As Havok stated, you can just use the Shutdown switch from command prompt. See options below.

Run from cmd.exe or just put into a .bat script as below (and you could just add this .bat to Windows scheduler if you wanted to schedule) - remove the "pause" if you want it to run straight away:

@cd /
@cls
@echo #Shutdown 10min script#
@pause
@shutdown /t 600 /s

There are a number of automatical shutdown programs on the net. You can use one of them; for example: Sweet Dreams.